Web sites of interest:
http://www.weatherwizkids.com/ Many links to sites about specific topics such as lightning, hurricanes, tornadoes, winter storms, and many more. Find links for forecasting. Also has links to fun sites such as weather folklore, jokes.

http://www.temperatureworld.com/tempcon.htm Online temperature converter Easily convert Fahrenheit to Celsius.

iPad apps:

Fahrenheit - ($.99) Weather and Temperature for both iPad, iPod, and iPhone for one fee. One of Apple's top weather apps for 2011.
I like this one because it can have multiple locations. You can track what weather is happening in the other classrooms.

Easy Weather and Temperature Converter - (Free) Convert Fahrenheit to Celsius and vice versa and more.

Lifecards - Postcards ($1.99) Use up to four of your photos to create a postcard of your school to share with other classrooms.